When the Boot Drive is No Longer Detected

Generally, if a SATA drive is configured as the bootable drive, then the computer relies on that drive to boot the computer and to launch Windows. It is the source of most of the computer's operations. So, if the computer suddenly stops detecting the bootable drive, this will almost certainly mean that the computer will fail to boot at all. Instead, some error message will occur, and it will become obvious that a serious problem has occurred.

One error in particular, however, is more important than others to watch out for. If a "SMART error" has recently appeared on your computer, this generally means drive failure is imminent or has already occurred. If you have received a SMART error, we strongly recommend that you stop everything and make an immediate backup of any and all important data contained on this drive that is not already backed up.See the section on SMART errors for more information.

When the storage drive is no longer detected

If a Serial ATA drive, installed as additional storage in your computer, was previously detected but is no longer detected, this set of troubleshooting steps will attempt to get the drive detected again, or to conclude whether the drive has failed and should be replaced.

If a "SMART error" has recently appeared on your computer, this generally means drive failure is imminent or has already occurred. If you have received a SMART error, we strongly recommend that you stop everything and make an immediate backup of any and all important data contained on this drive that is not already backed up.See the section on SMART errors for more information.

Prepare the Storage Drive

Once you connect a new Serial ATA drive in your computer as additional storage, there remains more to do to get your drive working.

First, please see Document ID: 196169 for more information on installing drives and Document ID: 188411 about the proper drivers in Windows (though if your computer's boot drive is SATA, there should be no need for additional drivers).

BIOS

The BIOS is a basic status monitor for the state of your computer and its devices.

Access the BIOS by rebooting the computer and, while it is in the process of booting, before the Windows screen appears, press the key that will open the BIOS. This key will vary by computer make and model, but it is often Escape, Delete, F1, or F2. Consult your computer manufacturer if you are unable to enter the BIOS.

Here are a few tips:

Sometimes the reboot will proceed too quickly for you to be able to press the BIOS key in time. In this case, shut down the computer and wait for it to cool a little (probably at least 5 minutes). Then boot the computer again and retry.

Please keep in mind that these contain information that has not been fully verified by Seagate, nor does Seagate possess in-depth or exhaustive knowledge of your motherboard BIOS, since the BIOS is the property of a different company.

Most new computers will automatically detect devices through the system setup program (CMOS or BIOS). As the system starts, the auto-detect feature may display the drive model number on screen. Seagate drive model numbers begin with the letters "ST". Some Serial ATA BIOS have a system setup that is not contained within the normal motherboard BIOS. If this is the case, the Serial ATA drive will only be displayed in this Serial ATA BIOS message. Please consult the motherboard or Serial ATA controller documentation for assistance with entering into the Serial ATA BIOS setup.
(Click to expand first image)
(Click to expand second image)

Before proceeding, please ensure that the SATA port to which your drive is connected is enabled. If in doubt, enable all SATA ports unless instructed otherwise by the BIOS.

Connect in an External Enclosure

If connecting the drive in another computer did not allow you to access the drive, or if you do not have another computer available, you can connect the drive via an external enclosure or adapter that will connect to the computer from one of the USB ports on the outside of the computer.
You will need:

a working computer; it can be either a desktop or a notebook

an external USB enclosure
A USB enclosure or SATA-USB connection adapter can be found at many computer stores and is inexpensive.

Troubleshoot the Computer

If the drive is detected normally in (My) Computer and/or Windows/File Explorer when installed in this external enclosure,
this means the drive is healthy.

However, since we already tested the drive in the original computer and it was not detected even at the most basic level, the BIOS, the source of the problem is either a limitation or another problem with the first computer. Check with the computer manufacturer for more information.

Please select an answer:

Repair Windows

Insert and boot from your Windows install disc to perform a Windows Repair/Restore.

Disconnect all external storage devices such as external USB, Firewire, and eSATA drives, jump/thumb/flash drives, cameras, and printers before proceeding with a Windows repair or recovery. Failure to disconnect such devices could result in serious data corruption.

Boot up the computer.

Insert your Windows installation CD/DVD into the CD/DVD drive.

Reboot the computer, and it should boot up into the Windows disc.

Select to perform a repair or restore action, and follow the steps provided there.

If the repair or restore fails, the following articles may be of assistance.

If the drive successfully passes the diagnostics (but the Windows repair/recovery failed), then the drive itself is most probably safe to continue using. You should therefore attempt to erase the drive and reinstall the operating system.
The simplest way to reinstall the operating system (and probably erase the data, though that does not happen every time) is to insert the Windows CD/DVD in the CD/DVD drive and then reboot the computer. The option to repair Windows should appear as well as an option to reinstall Windows. Since the repair has failed, simply choose to reinstall Windows.

This will very probably erase all data on the drive.

If that fails to reinstall Windows, a stronger erase is probably required. Seagate's utility SeaTools for DOS can perform a quick, a timed, or a full erasure (known as a "zero-fill") of the drive. In this case, a full zero-fill is probably the best option. This can take many hours depending on many factors including the drive capacity, so leave adequate time for this. If you are short on time, attempt a timed zero-fill of at least a few minutes.
Then insert the Windows CD/DVD in the CD/DVD drive and then reboot the computer. You should be able to install Windows as if from scratch.

Connect in an External Enclosure

To return the drive to proper working order, we must attempt to repair or reinstall Windows. This will result in erasing the data on the drive.
Before putting your data at risk, you should make a backup.

The easiest way to do that is to connect the drive via an external enclosure or adapter that will connect to a different computer from one of the USB ports on the outside of the computer.
You will need:

a working computer; it can be either a desktop or a notebook

an external USB enclosure
A USB enclosure or SATA-USB connection adapter can be found at many computer stores and is inexpensive.

Connect the drive inside the enclosure or to the adapter according to the manufacturer's instructions.

Power on the drive and enclosure, and connect it to the computer via USB. The computer can be powered on when you do this.

The drive should appear in (My) Computer and/or Windows/File Explorer.

Begin the backup action. If you are backing up the data to a different external drive, you may simply drag and drop.
Creating two different complete backups of your data, on two different storage media, is strongly recommended.

Repair Windows

Now that the data is backed up, insert and boot from your Windows install disc to perform a Windows Repair/Restore.

Disconnect all external storage devices such as external USB, Firewire, and eSATA drives and jump/thumb/flash drives before proceeding with a Windows repair or recovery. Failure to disconnect such devices could result in serious data corruption.

Boot up the computer.

Insert your Windows installation CD/DVD into the CD/DVD drive.

Reboot the computer, and it should boot up into the Windows disc.

Select to perform a repair or restore action, and follow the steps provided there.

If the repair or restore fails, the following articles may be of assistance.

If the drive successfully passes the diagnostics (but the Windows repair/recovery failed), then the drive itself is most probably safe to continue using. You should therefore attempt to erase the drive and reinstall the operating system.
The simplest way to reinstall the operating system (and probably erase the data, though that does not happen every time) is to insert the Windows CD/DVD in the CD/DVD drive and then reboot the computer. The option to repair Windows should appear as well as an option to reinstall Windows. Since the repair has failed, simply choose to reinstall Windows.

This will very probably erase all data on the drive.

If that fails to reinstall Windows, a stronger erase is probably required. Seagate's utility SeaTools for DOS can perform a quick, a timed, or a full erasure (known as a "zero-fill") of the drive. In this case, a full zero-fill is probably the best option. This can take many hours depending on many factors including the drive capacity, so leave adequate time for this. If you are short on time, attempt a timed zero-fill of at least a few minutes.
Then insert the Windows CD/DVD in the CD/DVD drive and then reboot the computer. You should be able to install Windows as if from scratch.

Connect in an External Enclosure

If connecting the drive in another computer did not allow you to access the data, or if you do not have another computer available, you can connect the drive via an external enclosure or adapter that will connect to the computer from one of the USB ports on the outside of the computer.
You will need:

a working computer; it can be either a desktop or a notebook

an external USB enclosure
A USB enclosure or SATA-USB connection adapter can be found at many computer stores and is inexpensive.

Troubleshoot the Computer

If the drive is detected normally in (My) Computer and/or Windows/File Explorer when installed in this external enclosure,
this means the drive is healthy.

However, since we already tested the drive in the original computer and it was not detected even at the most basic level, the BIOS, the source of the problem is either a limitation or another problem with the first computer. Check with the computer manufacturer for more information.

Seagate also recommends that you backup your data immediately. See Document ID: 190751 for more information.

If the diagnostics reveal no problem, then the booting problem means a different problem exists in your original computer. We recommend you contact the computer manufacturer for further support.

Remove the SeaTools for DOS CD.

Reboot the computer and launch Windows normally.

Attempt to access the data on the drive, in (My) Computer or Windows/File Explorer.Back up your data immediately. See Document ID: 190751 for more information. An external USB drive would be the simplest solution.

Connect in an External Enclosure

If connecting the drive in another computer did not allow you to access the data, or if you do not have another computer available, you can connect the drive via an external enclosure or adapter that will connect to the computer from one of the USB ports on the outside of the computer.
You will need:

a working computer; it can be either a desktop or a notebook

an external USB enclosure
A USB enclosure or SATA-USB connection adapter can be found at many computer stores and is inexpensive.

Connect in a Second Computer

If you have access to a second computer with a Serial ATA interface, you can (after powering down the computer, of course) connect the drive to another of the Serial ATA ports on the motherboard, as an additional storage drive.

If the diagnostics reveal no problem, then the booting problem means a different problem exists in your original computer. We recommend you contact the computer manufacturer for further support.

Remove the SeaTools for DOS CD.

Reboot the computer and launch Windows normally.

Attempt to access the data on the drive, in (My) Computer or Windows/File Explorer.Back up your data immediately. See Document ID: 190751 for more information. An external USB drive would be the simplest solution.

BIOS

If the drive is not even detected in Disk Management, we must confirm it is detected at the level of the motherboard. We can do that by checking in the BIOS. The BIOS is a basic status monitor for the state of your computer and its devices.

Access the BIOS by rebooting the computer and, while it is in the process of booting, before the Windows screen appears, press the key that will open the BIOS. This key will vary by computer make and model, but it is often Escape, Delete, F1, or F2. Consult your computer manufacturer if you are unable to enter the BIOS.

Here are a few tips:

Sometimes the reboot will proceed too quickly for you to be able to press the BIOS key in time. In this case, shut down the computer and wait for it to cool a little (probably at least 5 minutes). Then boot the computer again and retry.

Please keep in mind that these contain information that has not been fully verified by Seagate, nor does Seagate possess in-depth or exhaustive knowledge of your motherboard BIOS, since the BIOS is the property of a different company.

Most new computers will automatically detect devices through the system setup program (CMOS or BIOS). As the system starts, the auto-detect feature may display the drive model number on screen. Seagate drive model numbers begin with the letters "ST". Some Serial ATA BIOS have a system setup that is not contained within the normal motherboard BIOS. If this is the case, the Serial ATA drive will only be displayed in this Serial ATA BIOS message. Please consult the motherboard or Serial ATA controller documentation for assistance with entering into the Serial ATA BIOS setup.
(Click to expand first image)
(Click to expand second image)

Before proceeding, please ensure that the SATA port to which your drive is connected is enabled. If in doubt, enable all SATA ports unless instructed otherwise by the BIOS.

Connect in a Second Computer

If you have access to a second computer with a Serial ATA interface, you can (after powering down the computer, of course) connect the drive to another of the Serial ATA ports on the motherboard.

Power down the computer.

Connect the drive using known-good cabling to another of the SATA ports on your motherboard.

Boot the computer.

Once Windows has started, attempt to access the data on the drive, in (My) Computer or Windows/File Explorer.Back up your data immediately. See Document ID: 190751 for more information. An external USB drive would be the simplest solution.

Connect in an External Enclosure

If connecting the drive in another computer did not allow you to access the data, or if you do not have another computer available, you can connect the drive via an external enclosure or adapter that will connect to the computer from one of the USB ports on the outside of the computer.
You will need:

a working computer; it can be either a desktop or a notebook

an external USB enclosure
A USB enclosure or SATA-USB connection adapter can be found at many computer stores and is inexpensive.

Troubleshoot the Computer

If the drive is detected normally in (My) Computer and/or Windows/File Explorer when installed in this external enclosure,
this means the drive is healthy. You can further confirm the drive's health with a SeaTools for Windows diagnostic test.

However, since we already tested the drive in the original computer and it was not detected even at the most basic level, the BIOS, the source of the problem is either a limitation or another problem with the first computer. Check with the computer manufacturer for more information.

Seagate also recommends that you backup your data immediately. See Document ID: 190751 for more information.

Reset the Drive Letter

If the drive is no longer detected in (My) Computer or Windows/File Explorer but it is displaying a blue bar in Disk Management, Windows has probably lost track of the drive letter. Please follow these steps:

Lost Partition

A black bar in Disk Management means that the partition has become lost. At this point, we must ensure the safety of your data.
Is the data on this drive backed up elsewhere, or do you need to try to recover it?

If the drive passes the diagnostic but is still not detected in Disk Management, please attempt to update the Serial ATA drivers for your motherboard. Check with the motherboard manufacturer for assistance.

Connect in a Second Computer

If you have access to a second computer with a Serial ATA interface, you can (after powering down the computer, of course) connect the drive to another of the Serial ATA ports on the motherboard.

Power down the computer.

Connect the drive using known-good cabling to another of the SATA ports on your motherboard.

Boot the computer.

Once Windows has started, attempt to access the data on the drive, in (My) Computer or Windows/File Explorer.Back up your data immediately. See Document ID: 190751 for more information. An external USB drive would be the simplest solution.

Connect in an External Enclosure

If connecting the drive in another computer did not allow you to access the data, or if you do not have another computer available, you can connect the drive via an external enclosure or adapter that will connect to the computer from one of the USB ports on the outside of the computer.
You will need:

a working computer; it can be either a desktop or a notebook

an external USB enclosure
A USB enclosure or SATA-USB connection adapter can be found at many computer stores and is inexpensive.

Troubleshoot the Computer

If the drive is detected normally in (My) Computer and/or Windows/File Explorer when installed in this external enclosure,
this means the drive is healthy. You can further confirm the drive's health with a SeaTools for Windows diagnostic test.

However, since we already tested the drive in the original computer and it was not detected even at the most basic level, the BIOS, the source of the problem is either a limitation or another problem with the first computer. Check with the computer manufacturer for more information.

Seagate also recommends that you backup your data immediately. See Document ID: 190751 for more information.

In Device Manager, click the + sign next to Disk drives to expand the menu.

Locate the storage drive that we have been working on. It is usually identified by model number, beginning with ST.
Be sure that you have identified which is the boot drive (ie, the main drive) and which one is the storage drive, the one we are troubleshooting at this time. If you are unsure, go back into the BIOS to identify which drive is which.

Right-click on the storage drive (not the boot drive) and select Uninstall.

Getting Ready

Once you connect a new Serial ATA drive in your computer, there remains more to do to get your drive working.

First of all, often, users want to install a new drive in order to upgrade to a larger hard drive in their computer. This usually means that the user wants to copy all the data from the older hard drive to the newer drive, then install the newer drive as the bootable drive. To upgrade to a new drive, copying your data from the old drive to a new one, see Document ID: 201991.

Install Windows

If you are simply going to install a new copy of Windows (the operating system), you first need to format and partition the drive, and then install Windows:

Disconnect all external storage devices such as USB, Firewire, and eSATA drives, jump/thumb/flash drives, cameras, and printers before proceeding with a Windows repair or recovery. Failure to disconnect such devices could result in serious data corruption.

The Windows installation process should begin, as the computer boots from the installation CD/DVD.

Follow the guidance of the install program.
It will take you through a process of several steps, including partitioning and formatting the drive. You can choose the default setting - one big partition - or choose to partition the drive into multiple different partitions, as you prefer. It will then install Windows.

Once it is complete, it will most probably ask you to remove the CD/DVD and reboot the computer. Once this is done, you should be able to boot into Windows, and the install is complete.

If you have a 3TB or 4TB drive and the installation process indicates that the available capacity of the drive is much less than 3TB or 4TB, please see Document ID: 218691 and Document ID: 218619 for assistance.

Check Motherboard Age

Some older computer motherboards are unable to support modern Serial ATA drives.
If your motherboard only supports SATA1 (1.5 Gbits/sec transfer rate) and you are installing a SATA2 (3.0 Gbits/sec) or SATA3 (6.0 Gbits/sec) drive, the motherboard may not detect the drive. There are four options in that case:

Obtain an add-on controller card that can support more modern drives and connect the drive to that card.

(For Barracuda 7200.11 drives and older, as well as certain Barracuda 7200.12 models) You can place a jumper on the drive to slow it down to 1.5 Gbits/sec, so older motherboards can support it.

BIOS

The BIOS is a basic status monitor for the state of your computer and its devices.

Access the BIOS by rebooting the computer and, while it is in the process of booting, before the Windows screen appears, press the key that will open the BIOS. This key will vary by computer make and model, but it is often Escape, Delete, F1, or F2. Consult your computer manufacturer if you are unable to enter the BIOS.

Here are a few tips:

Sometimes the reboot will proceed too quickly for you to be able to press the BIOS key in time. In this case, shut down the computer and wait for it to cool a little (probably at least 5 minutes). Then boot the computer again and retry.

Please keep in mind that these contain information that has not been fully verified by Seagate, nor does Seagate possess in-depth or exhaustive knowledge of your motherboard BIOS, since the BIOS is the property of a different company.

Most new computers will automatically detect devices through the system setup program (CMOS or BIOS). As the system starts, the auto-detect feature may display the drive model number on screen. Seagate drive model numbers begin with the letters "ST". Some Serial ATA BIOS have a system setup that is not contained within the normal motherboard BIOS. If this is the case, the Serial ATA drive will only be displayed in this Serial ATA BIOS message. Please consult the motherboard or Serial ATA controller documentation for assistance with entering into the Serial ATA BIOS setup.
(Click to expand first image)
(Click to expand second image)

Before proceeding, please ensure that the SATA port to which your drive is connected is enabled. If in doubt, enable all SATA ports unless instructed otherwise by the BIOS.

If the drive is now detected in the BIOS, please proceed with the installation of Windows as mentioned previously.

Troubleshoot the Computer

If the drive is detected normally in (My) Computer and/or Windows/File Explorer when installed in this external enclosure,
this means the drive is healthy.

However, since we already tested the drive in the original computer and it was not detected even at the most basic level, the BIOS, the source of the problem is either a limitation or another problem with the first computer.

Connect in a Second Computer

If you have access to a second computer with a Serial ATA interface, you can (after powering down the computer, of course) connect the drive to another of the Serial ATA ports on the motherboard, as an additional storage drive.

Troubleshoot the Computer

Since the drive is properly detected in the second computer, and if it passed the diagnostic tests performed during the previous step, the source of the problem is either a limitation or another problem with the first computer.

Prepare the Storage Drive

Once you connect a new Serial ATA drive in your computer as additional storage, there remains more to do to get your drive working.

First, please see Document ID: 196169 for more information on installing drives and Document ID: 188411 about the proper drivers in Windows (though if your computer's boot drive is SATA, there should be no need for additional drivers).

Motherboard Compatibility

Some older computer motherboards are unable to support modern Serial ATA drives.
If your motherboard only supports SATA1 (1.5 Gbits/sec transfer rate) and you are installing a SATA2 (3.0 Gbits/sec) or SATA3 (6.0 Gbits/sec) drive, the motherboard may not detect the drive. There are four options in that case:

Obtain an add-on controller card that can support more modern drives and connect the drive to that card.

(For Barracuda 7200.11 drives and older, as well as certain Barracuda 7200.12 models) You can place a jumper on the drive to slow it down to 1.5 Gbits/sec, so older motherboards can support it.

BIOS

The BIOS is a basic status monitor for the state of your computer and its devices.

Access the BIOS by rebooting the computer and, while it is in the process of booting, before the Windows screen appears, press the key that will open the BIOS. This key will vary by computer make and model, but it is often Escape, Delete, F1, or F2. Consult your computer manufacturer if you are unable to enter the BIOS.

Here are a few tips:

Sometimes the reboot will proceed too quickly for you to be able to press the BIOS key in time. In this case, shut down the computer and wait for it to cool a little (probably at least 5 minutes). Then boot the computer again and retry.

Please keep in mind that these contain information that has not been fully verified by Seagate, nor does Seagate possess in-depth or exhaustive knowledge of your motherboard BIOS, since the BIOS is the property of a different company.

Most new computers will automatically detect devices through the system setup program (CMOS or BIOS). As the system starts, the auto-detect feature may display the drive model number on screen. Seagate drive model numbers begin with the letters "ST". Some Serial ATA BIOS have a system setup that is not contained within the normal motherboard BIOS. If this is the case, the Serial ATA drive will only be displayed in this Serial ATA BIOS message. Please consult the motherboard or Serial ATA controller documentation for assistance with entering into the Serial ATA BIOS setup.
(Click to expand first image)
(Click to expand second image)

Before proceeding, please ensure that the SATA port to which your drive is connected is enabled. If in doubt, enable all SATA ports unless instructed otherwise by the BIOS.

If the drive is now detected in the BIOS, please proceed with the installation of Windows as mentioned previously.

Troubleshoot the Computer

If the drive is detected normally in (My) Computer and/or Windows/File Explorer when installed in this external enclosure,
this means the drive is healthy.

However, since we already tested the drive in the original computer and it was not detected even at the most basic level, the BIOS, the source of the problem is either a limitation or another problem with the first computer.

Connect in a Second Computer

If you have access to a second computer with a Serial ATA interface, you can (after powering down the computer, of course) connect the drive to another of the Serial ATA ports on the motherboard, as an additional storage drive.

Troubleshoot the Computer

Since the drive is properly detected in the second computer, and if it passed the diagnostic tests performed during the previous step, the source of the problem is either a limitation or another problem with the first computer.

Please select an answer:

SeaTools

Seagate uses the SeaTools diagnostic software to test the SMART status of the drive. It also dives deeper to test the drive on other levels.

SeaTools' PASS or FAIL is the standard that Seagate uses to determine whether a hard drive is still in good working order, or is failing. A drive may be failing but continue to function normally for a short time, so SeaTools is often a better judge of whether the hard drive is failing than the drive's functionality at any given moment.
Therefore, if SeaTools indicates that the drive is failing, Seagate recommends backing up your data immediately and replacing your drive.

Drive Self-Test

Each Seagate hard drive engages in regular self-tests, and most computers automatically run regular SMART tests on the hard drive(s) installed on them. SMART tests indicate whether a drive is approaching imminent failure. Thus, if a SMART error appears suddenly, it virtually always means, unfortunately, that the drive is about to fail and should be replaced.

Third-party SMART

Black Screen

Alternately, this could be caused by the bootable drive's having failed or gone undetected . You may need to begin troubleshooting at the first step of the troubleshooting procedure for bootable drives.